Squamaria- erosas?
2807
PARMELIA erosa.
Toothed-edged Stellated Parmelia.
CRYPTOGAMIA Lichenes.
G e n . C h a r . Scutellce formed from the thallus, affixed
by a central point, the circumference free.
Disk of a different substance from the margin.
S p e c . C h a r . Thallus leafy, imbricated, pale greenish
grey, greyish white when dry; underside white,
with pale fibres ; segments much divided, rounded,
with minutely jagged edges. Scutellse orbicular,
flattish ; margin slightly elevated; disk
black.
S y n . Lecanora tribacia in part. Ach. Lick. Univ.
415. Syn. 191.
Squamaria tribacia in part. Hook. Brit.FI. 194.
O n trunks of old trees, particularly elms, on tiled roofs,
and on walls, not unfrequent in Sussex, and probably in
other parts of Britain, having been found as far north as
the Connel Ferry in Argyleshire; but the apothecia are
extremely rare. Two or three of them occurred many
years ago on a pear-tree at Hurst Pierpoint, and the specimen
was sent to Sir J . E. Smith, in whose collection it has
since his death been sought for in vain. Dr. Taylor has
observed them at the Dargle on Scotch Fir, and mentions
the plant in FI. Hibern., under P. tenella, as the Acharian
var. y exempta of that species, but in all probability distinct;
and Mr. Salwey has found a few on old specimens, one of
which is here figured, at Llanaber, near Barmouth. Acha-
rius expressed his intention to adopt the name suggested to
him, and now first published, but he subsequently joined
the plant with a Swiss Lichen, which, from his description
of the scutellse*, seems to be in fact quite different, under
. * “ Orbiculata thallo arete adnata, sed mox dilatata magna et irregularia
in ambitu lobato-crenata, disco semper piano pallide flavescente etmargine
thallode tumidiusculo elevato persistente albo crenas et lobos apothecii
semper coronante cincto.”—Lick. Univ. 1. c.